tonychu

before when i bought my 2001 cl type s a year ago i used to hit 340 or sometimes when i drive on the freeway but now all i am getting is 200 miles a tank! i have replaced my
air filter
oil every 4000 miles
checked my tires
cleaned my fuel injectors

i only have 90,000 miles on this and it is giving out only 200 miles per tank! what am i doing wrong guys? should ijust take it to a dealer to have them stick it hard to me? i also tried replacing my spark plugs but couldnt becuase of the 3 plugs in the back are impossible to get to. if you know hwo to get the last 3 in the back out please help with that too.

Shaftzx1

i ono why...but ive been gettin crappy gas mileage too... 115 at half tank... i see ur in the bay area... mabye its the gas here...who knows... i dunno, see what the other members of this forum have to say....

ps.. u messed up on the title of this thread...

OneFlyCL

iTrader: (1)

haha quit flooring it speedracer

getright

yo man, at first, after reading the title, i thought you might be crazy, hey 200 mpg ain't bad. But then i read the rest of the post, back to the point, what mods do you have? the spark plugs would definetly help but i'm not sure if it is enough to get you back to 340 miles a tank. Maybe you need a good fuel system cleaning. Not with the pour in the tank stuff, like a system flush or something. I don't know about going to the dealer though, unless you really trust and have a good relationship with them. You should also check your exhaust system. Just some thoughts to start with, good luck.

rtatsutani

I'd bet it is your plugs.

iisylentii

i have the same problem but i have a intake and headers on my car

treyster

Gotta be the plugs

typeR

rear plugs arent that bad...lay on the engine with your chest on the upper intake and get your right hand in behind from the drivers side,about where you see the large vacuum line that connects to the upper intake....i used to try to squeeze my arm in directly above each coil pack...thats a bitch and is the wrong way...now i could do all three plugs start to finish in 15 minutes

tonychu

i dont have my mods on my car none at all. should i use the ngk's they sell at kregen? anyone wanna help me do my plugs ill pay a fair ammount for the labor

falabarce

I actually started a thread about a week or so ago (I'm not working anymore so all days are the same for me now...hahaha).

At 1/2 tank, I was exactly at 104 miles....and that's w/o pushing the engine at all..that's actually about 75% highway miles!

Seems that we were getting some pretty SH***Y (and let me emphasize that word some more) gas here in Houston. I had the issue for about 3 tanks of gas. The most I got with highway when I usually get around 350-370 was about 230 before my gas light came on.

Now...two weeks later things seem back to normal. Even pushing it, I'm getting around 310 before the light comes on. So....I'd say be patient...the crappy gasoline is just making its way West...

Chr8808

iTrader: (1)

I've always gotten 200 mpTank
even in my old Legend

RaviNJCLs

iTrader: (4)

That's really low. I usually get about 250 a tank, and it's mostly city driving. On the highway I got 31 miles per gallon last trip. About 430 miles per tank.

I would have to say that it's the plugs.

2003type-s6

Yup, after I installed my headers I noticed I went from about 350 a tank to about 250..............probably because it was just so hard to keep my foot out of it w/ the headers

getright

headers will do that to ya, my mpg's have been steadily decreasing with each mod.

fuzzy02CLS

iTrader: (2)

This might sound strange, but are you guys hearing a faint ticking noise from the firewall area inside the car?

manitou

I have a 03 6speed and get 27-28miles per gallon city and 31-32hwy depending upon how much I hit the throttle. I have Comptech i/h/e, hypervoltage system & ground, and I drive it fairly hard.
I have air swirlers inside my AEM CAI. AEM pullys/Unorthodox Crank pully/17X8 Motegi lites with goodrich KDWs 235X45X17, Comptech springs/sways with Illuminas and Irridium plugs. No way your mileage should be that poor. Make the dealer fix it right.

Joshimoto

Headers should improve your gas mileage if anything, any mod you do to improve airflow whether it be in or out of you engine should impove you mileage, putting your foot down after you get the header is what makes it worse.

phitheta

its all about the city driving man, i barely around 250 per tank also and thats for two reasons. just installed a new cone filter in place of the box (like the icebox but without the actual box, kinda ghetto but it sounds great and no i havnt noticed a drop in performance, actually a slight gain) so ive been gunning it everytime i get a nice straightaway or underpass. also i very rarely get on the highway, my commute to school/work is only around 10 miles each and its all through stoplights and no cruising. "city" driving is killing me cause the engine is always climbing and rarely settling. other than that, buy a bike lol. i bought a crappy bike from sports authority and i try to ride it at least 2 days a week to school, makes the gas last that much longer till pay day.

nxthole72

I Live in the east bay near walnut creek. I mainly drive around 80-85% city and between 15-20% highway. My gas mileage is always around 290 before the gas light comes on. And let me tell you i dont baby my car around. Whenever i get gas i always do a calculation and i have never gotten less then 20.75 miles to the gallon. I only use cheveron supreme with techron. I have heard that chevron gives you the best gas mileage (dont know if that is b.s. or what).

fuzzy02CLS

iTrader: (2)

I asked about the ticking cause I had my purge valve replaced recently & I'm now getting way better gas milage. It was ticking.

I had a simliar issue on my 94 Explorer, & after I replaced that one as well, my milage went up.

It's a valve the purges the excess gas fumes back into the engine to be burned off.

If it's not working your MPG drops.

tonychu

hwo do i know if its the purge valve and how much did it cost you to replace it

fuzzy02CLS

iTrader: (2)

Mine was making noise & I'm under warranty. There's a whole test you can do. It's outlined in the service manual. I recommend buying one. www.helminc.com

evilstorm

i could get 400-430 miles a tank if i ran it out of gas otherwise, im closer to 375ish when i start to get nervous and fill up.

EricL

Suggestions/considerations

Try some freeway only driving first. Drive at 65-70 MPH -- preferably during a non-busy hour on a flat highway/freeway. Fill-up and check mileage by using the same station/pump to fill-up and make sure you drive smoothly (leave enough room between you and other drivers) to be able to avoid getting on and off the gas pedal. BTW, driving smoothly can help reduce the load on the auto tranny's torque converter.

If you don't get 27-34 MPG as described above (depending on temp, headwinds, etc), something is probably messed up. If your plugs were really bad, you would probably get some error codes tossed. I get over 30 MPG on the freeway and sometimes get 15 MPG in town.

If you drive in the city, forget about comparing mileage to other folks; IMO, there are just too many variables that impact gas mileage. We have a four-banger that gets 15 MPG -- in town -- due to the horrible congestion. Hell, the car is sitting in traffic about 80% of the time and rarely gets to move at a constant speed.

You can also try to drive "smoothly."

Things to look at (in addition to the things mentioned above):

Change of tires?
Low tire pressure?
Change of gas supplier?
Change of seasonal gas?
Alignment issues?
Weight in car?
Lead foot?

(I left out all kinds of mechanical/engine issues)

YMMV

andyjl

my mileage seems to have taken a hit as well,, at about half tank i get around 130-140 which is pretty shitty. It could be that i'm driving mostly city now since last year i drove all highway which gave me around 200 at half tank. But i'm thinking i should be getting better mileage at half tank (~170 miles at half) than what i 'm getting now assuming city is suppose to be around 20mpg with our cars.

Could my sparkplugs need to be replaced? I'm at 41k miles now and i think sparkplugs are suppose to last a lot longer than that?

shinybluecls

city driving i usually get about 150 at a half tank on a good week. i'm at about 57k and havent changed my spark plugs but i might change them soon.

a faint ticking noise from the firewall might be valve noise. depending on the mileage of your car and how you drive(conservative or flooring it all the time) you might need a valve adjustment .

also...mods such as intake and headers will INCREASE your gas mileage not decrease. The reason most people see a decrease in gas mileage is because they drive their cars harder after mods.

jcw497794

I live in mid Missouri and my 01 cl type s has 102k on it. I just came back from a road trip and was able to get 31.2 miles per gallon with the cruise set at 72mph. In town I only get 25, millage has never been a problem. I do have a problem with my SRS light being on and with my HID head light coming on and then going off.
Are you seing performace decrease? I would check my spark plugs, wires, and even look into an aftermarket coil pack like jacobs. You could be wasting a lot of fuel through your emmissions.

GreenMonster

I get about 21 mpg... heavy foot, lots of quick acceleration, mostly highway, but I get caught in stop and go traffic alot... I've kept a log of my gas comsumption since I bought the car... 250 miles on the last tank (12.27 gal fillup, I don't like to run the tank too low).

Best mileage has been 26 mpg on a trip to Maine...

tonychu

i just got my spark plugs replaced took me about 2 hours to do all 6 of them. we'll see in time if that fixed the problem

Nivek_M4

Wow, what a big variance in MPG. Since I got my car I get consistant 22 around town and 32 hiway. The 32 was on a 700 mile drive with the cruise on at 84mph. (summer w a/c)

Sly Raskal

iTrader: (1)

Have you guys checked your O2 sensors that's usually the main culprit in poor gas mileage.

Second to that is dirty air filter, bad plugs, bad fuel injectors or just a lead foot.

I've got 122K+ on my 03' CL-S and I'm averaging about 350miles per 14 gallons ~ 25mpg and that's with stop and go traffic in so cal 5 days out of the week for my 60 mi roundtrip commute for work/home.

tonychu

how i check my 02 sensor?

Sly Raskal

iTrader: (1)

If you have an obd2 reader you'd use that to check your o2 sensor.

If not, you gotta take it to a service shop to have them read it to check it.

tonychu

man im only getting aroun 220 now afte ri did all those tune ups

Sly Raskal

iTrader: (1)

perhaps it's the way you're driving?

I've heard that the CPU's in our cars adjust the fuel/air ratios and everything based on how you drive. the more drive with a lead foot, the more gas it'll drink.

Try driving really easy on the car for a few days at least and you may start to see a difference.


I noticed in my car for a while when I was driving hard i'd average 275-300. Then I started being really easy on the gas, and my mileage shot up to 350 after a week or so of easy driving.

Sly Raskal

iTrader: (1)

You may want to reference this thread....

https://acurazine.com/forums/ramblings-12/es300-next-gen-176188/

OneFlyCL

iTrader: (1)

HELP!! i just installed a comptech icebox and for some reason i m getting 110 at half tank!!! anybody has that experienced that?

Sly Raskal

iTrader: (1)

are you driving it with a lead foot?

OneFlyCL

iTrader: (1)

not really.... i drove pretty hard on it at first to test out the icebox....but after filling up a full tank, and driving it pretty easy i notice my gas milage was terrible. i dont think it should be this bad at 70K.
Oh yea i didnt get a coolant hose for the icebox so i'm using my stock one, you think that would make a difference?

artbran

iTrader: (2)

I lately have been gettin 200-250 a tank but then again you have to factor in that my tranny was on its last toe. I mean now its sitting in my garage totally dead.